Duetto Fuses

Can anyone help me with fuses on my van, a 2007 Duetto on the MWB Mk 7 Transit.

Under the drivers seat are 3 fuses and a relay.
I presume the relay cuts the habitation power when the ignition is on?
The 30a fuse seems to be all the habitation electrics,
The 20a fuse is the fridge 12volt,
What is the other fuse?
There are 2 fuses under the o/s seat for the Ebespacher space heater,
Is there a fuse for the gas water heater?
Is there a fuse for the main water pump?
I've found the fuse for the cassette pump, but what a crazy place to put it;- at arms length inside the cassette housing after the cassette is removed. Not one to change at night in the rain!
Are there any more I should know about?
Thanks

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frederic

That's interesting Frederick. Recently we had the 20A Fridge fuse in the battery box relay+fuse unit burn out the housing. My electrician said it had been taking too much current over a period of time but not sufficient to blow the fuse. He replaced it with a heavy duty fuse as you have done. Our Eberspacer has the 2 fuses under the side seat, but the supply also runs through the 30A fuse under the driver's seat, which means, I think, that you can't run the Eberspacher & the engine at the same time as Ignition ON = Habitation Off. Sounds like it may be a good idea to run a new dedicated supply to the Eberspacher.
Do you think the water pump & water heater are simply protected by the 30A Habitation fuse?
Do you know what the 3rd fuse in the battery box relay unit is for? (I've pulled it but can't see what it controls).
Also, - as you've obviousely given this some thought, - surely the rear battery on the Transit is the cranking battery, but this is the one AS have run all the habitation electrics from. I'd have thought they should run off the front (Auxiliary) battery?

One generic observation (i.e. not specific to the Duetto): typically, A/S install an Eberspacher in such a way that it will run with ignition off or on, so before considering a change to the wiring, I would check for sure to confirm your theory that it won't operate with the ignition on!

Hi All
I’ve made a bit more sense of this, if you’re interested.
Photo attached of the relay/fuse unit under the drivers seat with damaged 20A Fridge supply & alternative fuse visible. I’ve established that the:
30A fuse fed from Aux (Front) Battery  protects Eberspacher Diesel Heater & relay which shuts off Habitation electrics (except Eberspacher) when Ignition ON, ie: lights, water pump, gas heater & fridge ignition. (ie: Feed splits after fuse, 1 to Eberspacher, 1 to Relay, Eberspacher always live, Relay ignition controlled)
20A fuse protects Fridge on 12v when van running
20A fuse fed from Cranking (Rear) battery with Red/blue cable. Purpose unknown.
So, you are right, its possible to run the engine when starting the Eberspacher, but only at the expense of all other Habitation electrics going off. I note that as I think you observed that the Eberspacher runs poorly, or not at all, if the Aux battery is low.
My solar panel charges the cranking battery first, and then the auxiliary battery, but the Zig unit doesn’t swap over, so if I’m on EHU and leave the Hab switch to “Vehicle” the Aux battery can run flat, unless it’s very sunny!
At the rear inside of the driver’s seat box is a red cover which I managed to pry off today. This hides a live terminal from the Aux battery. I think this is fused under the black panel at the back of the battery box, but I can’t get into this without removing the seat and battery clamps.

Nice pics
Its worth putting a 'contact lube' on the fuse contacts after ensuring that they are clean especially the Eber fuse connected to the green 30A 'small' which is the one I had the overheating trouble with.
Went over all the relays and multiplug contacts with cleaner and lube especially the wiring harness of the Eber.
On the later models there were more 'individual' fuses as A/S realised that they could not just hang all auxiliary components on one large fuse.
I don't have the A/S wiring Diag. (a copy for my files would be nice) now as it went with the 2009 Duetto which was blessed with the multi switch auxiliary control panel not the later touch screen.
frederic

for info

Yes relay/fuseblock is bolted to the box, note free turning bolt which when bolted to box side rotated when trying to undo so had to cut a slot in bolt to stop it.
And yes especially when weather is cold, its best to fire up the Eber. with the engine running until its past its glow plug startup phase (about 1-2 mins) as this boosts the voltage available as the alternator is powering the charging cct. Also if able have fitted a separate thermistor located in the habitation area as the one built in is in the return airway close to the heater which as we all know is in the coldest place possible!! Especially in the Topaz where the return air inlet is in the drivers footwell. 
frederic

More confusion! I thought I'd got this sorted, as above, but today, checking something else, discovered that if the Habitation Panel Charging switch is on "Habitation" then all the 12v electrics bar the Diesel heater run, even with the 30A Fuse &/or Relay removed.
I'd assumed that the Zig simply topped up the auxiliary battery, and then everything ran off that, but apparently not. There must be a separate 12v feed from the Zig into the habitation electrics, and I can't find any other fuses. Is this likely, or is there a crossed wire somewhere?

Our Eber. ran when the Hab. switch was charging the battery. One could see the voltage drop when the glow plug was activated and return to normal when the Eber was running
frederic
Any chance that you could post a wiring diag from your handbook please

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Any further updates folks?
frederic

We have a 2007 Duetto P3051, sorry to disappoint anyone but the drawing above does not co-incide with the electrics in ou P3051. In 2007 I asked AS for a valid drawing and they said there was'nt one. They gave me a drawing of the loom used which they said was used and connected up by electricians ad-hoc on the workshop. I also managed to get a couple of sheets from Plug-in-Systems who made the control panel and multi pole connections. These proved to be accurate but very difficult to use. I ended up re-wiring most of it for many reasons, not just the melting fuse and relay holder under the drivers seat as above in this thread.